The present invention relates to an improved four-sided carton adapted to be used for packaging popcorn and more particularly to a four-sided carton for popping popcorn in a microwave oven.
Hertofore, numerous popcorn cartons have been made for packaging popcorn and for popping popcorn in microwave ovens. Such cartons are usually made of paperboard or paper/poly laminates and are sometimes multi-sided or bag shaped. An example of such a paperboard carton is shown in U.S. Pat. No. 4,279,933.
Some such existing popcorn cartons do not have a high energy efficiency and may be subject to some heat losses. The corn kernels and the heat should optimally be concentrated in a small compact area and the configuration of the package should be such that the heavier and smaller unpopped kernels will tend to fall back into that area of greatest energy concentration during the popping process. Hence, the outer carton must be capable of being positioned in a microwave oven so that there is maximum energy efficiency and minimum heat loss.